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Machine Learning

(2)

Today’s Class

People Involved

Is Machine Learning affecting us?

What is Machine Learning?

History

Example Systems that use Machine Learning

Related areas

What should you learn?

Course Outline

(3)

People Involved

Instructor

• Saket Anand

• Office Hours: Mondays, 1PM-2PM, Venue: A-510

• Email: [email protected]; Phone: +91 11 2690 7425; Campus Ext: 425 • Course Page: TBD

• Discussions/Submissions: Google Classroom

Teaching Assistants

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Is Machine Learning Really Affecting Us?

Gmail and Google Search

• Smart Reply, Personalized Ads

Social Media Feeds

• Facebook, LinkedIn, Instagram

Music and Media Streaming

• Netflix, Youtube, Spotify

Maps, Navigation and Travel

• Google, Uber, Ola

Banking and Finance

• IVR, Fraud Protection

Online Shopping

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Autonomous Driving

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Natural and Spoken Language Processing

Conversational Agents and

Translators Optical Character Recognition and Translation

Apple

Siri AssistantGoogle Microsoft Cortana

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Image Analysis and Computer Vision

iPhone Xs vs. Pixel 3’s Night Sight Mode

(9)

Google’s panorama generation

thought a skier was a mountain!

Pitfalls and Perils of ML

Chinese billionaire’s face

identified as jaywalker

• Surveillance system

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Pitfalls and Perils of ML

Claim: Machines have a better

“gaydar”

• If true: privacy breach

• If false: reinforces prejudice

Uber hits and kills a pedestrian in

Tempe, Arizona, US

“DeepFakes” used to generate fake

porn using Hollywood celebrity

facial images

1Source: The Guardian

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Efforts towards AI for Social Good

Microsoft AI for Earth

• Climate Change, Agriculture,

Biodiversity and Water

Google AI for Social Good

• Flood prediction

• Cardiac risk prediction

• Mapping global fishing activity

Wadhwani Institute for AI

• Focus on Societal problems in

India: Health, Agriculture, Education, Financial Inclusion

Center for AI in Society, USC

• Focus on public health, social

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Source: Rolnick et al., “Tackling Climate Change with Machine Learning”, ArXiv, 10thJun. 2019 - 22 authors from 16 organizations

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Vision for Wildlife

from conservation to conflict management

Individual Identification in Camera Trap Images

~31,000 images of ~1650 individual tigers (`13-`14): Over 70% tigers out of estimated population

Intelligent Wildlife Monitoring

Goal: automatic indexing of image

datasets by species and individuals

Applications: camera-trap based

population monitoring; crowd-sourced reporting of human- wildlife conflict

Saket Anand Vision / Learning

Prof. Y. V. Jhala

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IIITD’s Autonomous e-Rick

Vision and Range sensors

Drive-by-Wire setup

Alexander Fell Embedded Systems

Now at SIT, Singapore

Saket Anand Vision / Learning

P. B. Sujit Robotics & Control

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What is Machine Learning?

It is an important sub-area of AI that seeks to answer the following

question:

How can we build computer systems that automatically improve with experience?

More Formally:

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Machine Learning Tasks (T)

Classification or Pattern Recognition

Regression or Prediction

Density Estimation

Clustering

Synthesis or Sampling

Ranking

Recommendation Systems

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Performance (P)

A quantitative measure to evaluate performance

• Usually Task specific

Classification

• Accuracy or Error Rate

• Weighted versions of accuracy (e.g., in unbalanced data)

Regression

• Error measure such as ‘mean squared error’

• Application dependent – many medium errors or few large errors?

Density Estimation

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Experience (E)

Supervised Learning

• Labelled data – (Data, target value)

• Target value could be category/class labels, real value, real vector, etc.

• Classification, Regression

Unsupervised Learning

• Only data, no labels

• Density Estimation, Clustering

Semi-supervised Learning

• Some labelled data and lots of unlabelled data • Multiple-Instance Learning

Reinforcement Learning

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Example Systems that use ML

Google Search

Google Car

Amazon’s recommendation system

Adobe’s Optical Character Recognition (OCR)

Facebook’s face tagging, news feed

Apple’s Siri, Microsoft’s Cortana, Amazon’s Echo (Speech Recognition)

Microsoft Kinect + Xbox

Autopilots in aircrafts

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An Incomplete History of Learning

• Turing Test (1950)

• Machines do very poorly

• Rosenblatt’s Perceptron (1960’s)

• Kickstarted the mathematical analysis of

the learning process

• Key idea behind Support Vector Machines

(SVMs) and Neural Networks

• Construction of Fundamentals of

Learning Theory (1960-70’s)

• Focus on generalization capability of

learning machines

• Performance on unseen data

• Regularization for ill-posed problems

• e.g., linear equations for ill-conditioned

matrices

• Neural Networks (1980’s)

• Connectionism

• Back-propagation [LeCun, `86] • CNNs, RNNs

• SVMs (1990’s)

• Margin Maximization

• Kernel Methods to handle non-linearity

• Deep Learning (>2006)

• Hinton, Bengio, LeCun at forefront • Abstract Representations

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Related Areas

Statistical Modelling and Inference

• Regression, Hypothesis Testing, Significance Testing

Signal Processing (Data = Signal)

• Detection and Estimation

• Hypothesis Testing (Classification/Detection) • Estimation (Regression – Error Minimization)

• Representation of signals –

• Fourier, Wavelets, etc.

• Compressed Sensing and Sparse representations.

Optimization

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What should you learn?

Modelling a learning problem

Various algorithms (techniques) for solving ML problems

Pitfalls while designing ML systems

• Modelling, Generalization, Regularization & Model Selection, (hyper)-Parameter tuning,

Overfitting, Underfitting

Importance of Domain Knowledge

• Not treating ML techniques as a black box

• Simplify the learning problem by using domain knowledge

Engineering Tricks

• Debugging ML systems

Tools

(23)

Course Outline

Topics:

• Empirical Risk Minimization

Framework

• Linear Models for Regression and

Classification

• Linear & logistic regression

• ML in Practice

• Training, Validation and Testing • Underfitting/Overfitting

• Hyperparameter search • Cross-validation

• Decision Trees and Random

Decision Forests

• Support Vector Machines

• Primal and Dual Formulations • Kernel Methods

• Neural Networks

• Loss and Optimization

• Convolutional Neural Networks • Generative Models

• Unsupervised Learning

• Clustering – k-means, Spectral (if

time permits)

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Prerequisites

Required

• Linear Algebra

• Probability and Statistics

• Advanced Calculus (mainly, vector differentiation) • Introduction to Programming (Python)

• In reality you would need much more than an introduction

Desired

• Optimization

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Learning Outcomes

Explain the different types of learning problems along with some

techniques to solve them

Model real-world problems, apply different learning techniques and

quantitatively evaluate the performance

Identify and use advanced techniques with the help of existing

machine learning tools and libraries

Analyze performance of ML techniques and comment on their

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Administrivia

Course Webpage: TBA

• Access through my page as well

Google Classroom Page (HW Submission/ Discussion): TBA

Reading Material

• Textbook & Lecture Notes (mostly from Andrew Ng’s Stanford Course) and papers

posted on website and classroom

Textbook:

• Understanding Machine Learning: From Theory to Algorithms, Shai Shalev-Shwartz

and Shai Ben-David, Cambridge University Press, 2014

References* :

• Machine Learning, Tom M. Mitchell, McGraw Hill, 1997

• Pattern Recognition and Machine Learning, Christopher M. Bishop, Springer, 2006 • Pattern Classification, Richard Duda, Peter Hart and David Stork, 2nd ed., Wiley, 2006

(28)

Administrivia

Programming platform: Python

Grading Scheme:

• HW (4 Theory+Programming)– 30%

• Quiz (best 3/4) – 10% (No re-tests whatsoever) • Project & demo– 25%

• You can choose topics suggested by us OR pick your own

• Mid-sem – 15% • Final – 20%

Absolute Grading:

• ample opportunity to make through extra credit questions!

Grade A A- B B- C C- D F

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Plagiarism Policy

IIIT-Delhi policy:

https://www.iiitd.ac.in/education/resources/academic-dishonesty

Zero Tolerance

• Updated Institute policy will apply

• All plagiarism cases will be on record for your tenure at IIIT-Delhi

All code and reports will be checked for plagiarism

HW theory questions may be asked in exam or quiz as is

• If correct in HW and incorrect in exam, HW question will be marked zero

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Next Class

Learning Problems and the Empirical Risk Minimization Framework

Loss Functions for Classification and Regression

Evaluation Metrics for Classification

Welcome Quiz (Linear Algebra, Probability & Statistics, Vector

References

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